1. Field of the Invention
The present invention relates to an ionizer, which generates ions in the vicinity of an electrode by application of a voltage to the electrode.
2. Description of the Related Art
In Japanese Laid-Open Patent Publication No. 10-064691, Japanese Laid-Open Patent Publication No. 2000-058290, and Japanese Laid-Open Patent Publication No. 2007-066770, technologies are disclosed in which ions are generated in the vicinity of electrodes by application of high voltages to the electrodes, and the generated ions are released toward an object to be neutralized, whereby static charges that charge the object can be removed and the object is neutralized.
More specifically, in Japanese Laid-Open Patent Publication No. 10-064691, it is disclosed that a high voltage of high frequency, which is generated by a high frequency oscillation circuit, is supplied to two voltage double rectifier circuits. A positive polarity DC high voltage, which is rectified by one of the voltage double rectifier circuits, is applied to one of the electrodes through one resistor, and a negative polarity DC high voltage, which is rectified by the other of the voltage double rectifier circuits, is applied to another of the electrodes through another resistor.
Further, in Japanese Laid-Open Patent Publication No. 2000-058290, a technique is disclosed in which a series circuit made up of a positive polarity high voltage generating circuit and a resistor, and a series circuit made up of a negative polarity high voltage generating circuit and a resistor are connected in parallel with respect to an individual electrode. In this case, by alternately operating the positive polarity high voltage generating circuit and the negative polarity high voltage generating circuit, positive polarity DC voltages and negative polarity DC voltages are generated alternately and applied to the electrode.
Furthermore, in Japanese Laid-Open Patent Publication No. 2007-066770, a technique is disclosed in which a series circuit made up of a positive polarity high voltage generator and a semiconductor switch, and a series circuit made up of a negative polarity high voltage generating circuit and a semiconductor switch are connected in parallel with respect to an individual electrode. In this case as well, by alternate operations of the positive polarity high voltage generator and the semiconductor switch and the negative polarity high voltage generator and the semiconductor switch, positive polarity DC voltages and negative polarity DC voltages are generated alternately and applied to the electrode.
On the other hand, in Japanese Laid-Open Patent Publication No. 10-108480, a high voltage switching circuit is disclosed, which can be applied to an ionizer. The high voltage switching circuit is constituted by a positive polarity DC voltage source and a negative polarity DC voltage source, together with four semiconductor switching elements. In this case, by controlling ON and OFF timings of the respective semiconductor switching elements, a positive polarity DC voltage and a negative polarity DC voltage are applied alternately to a load.